1. Field of the Invention
This invention relates to processors, and more particularly, to techniques for providing flexible cache directory structures within a multiple-core processor.
2. Description of the Related Art
With increasing demands on functionality and performance as well as improved fabrication techniques, newer generations of processors and other integrated circuits have significantly higher levels of integration than their predecessors. Transistor counts in the hundreds of millions on an integrated circuit are not uncommon, and transistor counts of over one billion are inevitable.
Despite advances in integrated circuit fabrication processes, manufacturing devices having high transistor counts can be difficult. The number of transistors on an integrated circuit device results is correlated to the number of opportunities for defects to occur during the manufacturing process. The large number of defect opportunities present in the manufacturing process may in turn lead to a low yield and a significant number of scrapped parts. The low manufacturing yield may result in a higher per-unit cost for good units, and in some cases can make the manufacture of a design economically unfeasible.
Additionally, in some instances, different market segments may exist for compatible versions of processors and other types of integrated circuits having price and performance characteristics specific to a particular market segment. However, given the complexity and expense of designing a single version of a processor or other integrated circuit having a large transistor count, it may be impractical to separately design and manufacture a processor for each of several different market segments.